You never, ever want to skimp on an overcoat. This is something that most of us learn the hard way, like when we're in Chicago in December and we're w-w-wishing we'd spent more on a coat that, you know, worked. The most versatile option is a cashmere or wool single-breasted design that hovers just about the knee. Wear it anywhere, and if chosen carefully, you can wear it for years.